Pushbutton structure



July 20, 1965 A. J. CLARKv PUSHBUTTON STRUCTURE 2 Sheets-Skaai l Filed Dec. 21, 1961 INVENTOR ALFRED J CLARK {Ma/v #MQ ATTYS.

July 20, 1965 A. J. CLARK 3,?.55

PusHBUTToN STRUCTURE Filed Dec. 21. 1961 2 Sheetsmhee' 2 INVENTOR. ALFRED J. CLARK ATTYS.

United States Patent O 3,195,359 PUSHBUTTON STRUCTURE Aifred d. Clark, Palatine, lll., assigner to Motorola, Inc., Chicago, Ill., a corporation of illinois Filed Dec. 21, 1961, Ser. No. 161,162 d Claims. (El. i4-19.33)

This invention relates to pushbutton tuning mechanism for radio receivers and more particularly to an improved locking device for use in presetting an adjustable pushbutton structure to permit repeated selection of a given station.

In radio tuners it is common to provide an adjustable cam member supported on a slidably mounted plunger rod. The cam member engages a treadle bar structure, including a pair of parallel members mounted on a rotatable carriage, coupled to tuning elements associated with a resonant circuit. In such mechanisms the cam member is fixed at a certain angle with respect to its supporting plunger rod so that as the rod is moved with respect to the parallel members, the cam member engages the parallel treadle bar members and brings them into alignment with the surface of the cam member. This sets the carriage and the resonant circuit to the proper adjustment for reception of a particular station.

Devices of this type which have heretofore been available have .the disadvantage in that they require a large number of components. Furthermore, their construction has required securing the'various components together by means of rivets resulting in relatively high labor costs due to the assembly time required for these operaitons.

It is an object of this invention to provide a locking device for use in presettable pushbutton mechanisms which is reliable of opera-tion and contains only a few parts.

Another object of the invention is to provide a locking device for use in presettable pushbutton tuning mechanisms which is low in cost and lends itself to automation.

A further object of the invention is to provide a locking device for use in presettable pushbutton tuning mechanisms which is capable of rapid assembly without tools.

A feature of the invention is the provision, in a pushbutton plunger system, of a plunger rod havnig a T lug thereon and an actuating bar with a corresponding guide slot therein, whereby the plunger rod and actuating bar are held in relatively slidable assembled relation.

Another feature of the invention is the provision of a pushbutton plunger system having a cam member adapted to be locked between a plunger rod and a locking lever, wherein a pivot post on a flat surface of the plunger rod cooperates with an opening in the cam member for removably mounting the cam member on the plunger rod, and the locking lever holds the cam member on the pivot post and locks lthe same in a fixed position.

Another feature of the invention is the provision, in a pushbutton plunger system having a plunger rod and a locking lever, of a slidable actuating member having an integral locking portion thereon in the shape of a hook which engages the locking lever and which is shaped to permit easy assembly of the system by insertion of the plunger rod and locking lever into the hook shaped locking portion through the open side thereof.

In the drawing:

FIG. 1 is a plan view of the pushbutton plunger assembly of the invention in locked position;

FIG. 2 is a side elevation thereof;

FIG. 3 is a half section thereof;

FG. 4 is a half section thereof in unlocked position;

FIG. 5 is a perspective view of the T lug and slot of the pushbutton plunger assembly with a partially disassembled assembly shown in phantom;

Patented .July 20, 1955 ice FTG. 6 is a section View taken along line 6--6 of FTG. 2;

FIG. 7 is a half section of a second embodiment of the invention;

FlG. 8 is a plan View thereof;

FIG. 9 is a half section of a third embodiment of the invention;

FIG. 10 is a partial plan view thereof; and

FIG. ll is a perspective View of a part of the third embodiment.

The invention provides a mechanism for locking and releasing a cam member on a plunger rod in a pushbutton control mechanism such as the tuning apparatus for a radtio receiver. The plunger assembly is of the push-to-lock type. A slidable actuating bar is operable by the pushbutton. The plunger rod is slidably and removably attached to the actuating bar for rapid assembly.

A cam member is rotatably held by a projection on the plunger rod. A resilient locking lever has one end xed relative to the plunger rod, adjacent the cam member, and its other end free. The surface of the lever is spaced from the side of the plunger rod so that the cam member is positioned between the plunger rod and the lever and held on the projection by the lever. A raised or arcuate portion of the resilient lever adjacent its free end is engaged by a hook shaped slidable locking porti-on of the actuating bar to move the raised portion of the lever toward the plunger rod thus causing the lever to apply pressure on the cam member to lock its rotation. The cam member is unlocked by sliding the locking portion out of engagement with the raised portion of the locking lever. A Spring member positioned between the locking lever and the plunger rod holds the locking lever against the locking portion to release pressure on the cam member to unlock it. The slidable locking portion is hooked shaped to permit insertion of the tongue and plunger rod through the open side during assembly. After the assembly has been set with the cam member in a locked position, inward movement of the pushbutton causes movement of the slidably mounted plunger rod and actuation of the tuning treadle of the mechanism to the angular position of the cam member.

Referring to FIG. 1, pushbutton 1l) is shown protruding partially through the face plate of a radio receiver, a portion of which is represented at 12. Slidable actuating bar 14 is xed to and operable by pushbutton 10. The actuating bar 14 in .turn operates plunger rod 20 which controls the tuning mechanism of the radio receiver. As may be seen more clearly in FIG. 5, actuating bar 14 has a guide slot 16 formed therein. T lug 1S, which is part of plunger rod 20, is removably tted into guide slot 16 and is slidable therein.

Plonger rod 20 has a projecting pivot portion 22 extending from one side. Cam member 24, which is of generally semicircular shape, has an opening for receiving pivot portion 22 to provide a pivot mounting of the cam member 2li with respect to rod 2d. Plunger rod Ztl has a hanged portion 26 having a key slot 2S therein extending on the opposite side from T lug 18. A resilient locking lever 3@ has on one end a locking key portion 32 which is insertable in key slot Z8. Locking lever 30 is disposed along the length of plunger rod 20 in a direction away from push-button 19 and spaced from plunger rod 26B to permit positioning of cam member 24 between the plunger rod and the lever. Cam member 24 is thereby held on pivot portion 22 by lever 3f). Placed between locking lever 30 and plunger rod 2li, to bias the two apart, is leaf spring 25. Spring 25 is positioned by means of an eX- truded locating pin 27 on locking lever 3l), and by a locating tab 29 on the spring fitting in locating slot 31 on plunger rod Ztl. .(See FIGS. 3 and 4.)

b At the opposite end of locking lever 30 is an arcuate or raised portion 34. When raised portion 34 is moved close to plunger rod 20, actuating bar 14 is provided with a hook-shaped integral locking portion 38 fashioned therefrom. Locking portion 38 encloses plunger rod Ztland `locking lever 301eaving an opening on one side, the advantage of which is explained at a later` point in this, specication.

There is shown in`FIG. 2 one of a plurality of slug tuned coil units 40 which are supported by the chassis of the tuner represented at 42. The units 40 maybe part of resonant circuits in a radio receiver as are known to those in the art. vThe movable slugs 44 of the units 40 are fase tened to a slidable portion of carriage 46 by means of screw rod 48 and threaded anchor 50.` Carriage 46 also includes a treadle structure comprising a pair of parallel bar members 52 mounted on an arm S4 rotatable about an axis midway between the bar members. connects the slidable portion of carriage i 46 to an extension of the arm 54 so that as bars 52 ar-e rotated about their axis, carriage46 and slugs 44 attached thereto are moved to effect continuous tuning of the coil units 40.

To x the cam member 24 ata desired angular position, `for pushbutton operation of the tuning apparatus,`

unlocked by drawing pushbutton outwardly from the` face plate kof the receiver 12 therebyk drawing with it actuating bar 14. It should be noted that in normal position spring 58 will cause pushbutton 10 to yprotrude further from receiver face plate 12 than is indicated in FIG. 2, by biasing butt portion 60 of plunger `rod 20 against vthe chassis 42. Plunger` rod and hence locking lever 3l) will remain fixed due to butt portion 60 lengaging chassis 42; The results of this operation are particularly illustrated in FIGS. 3 and 4.' FIG. V3 shows the device in a locked position with locking portion 3S holding raised portion 34 relatively close to plunger rod 20. Upon withdrawing actuating bar 14 which slides on T lug 18 in guide slot 16, the device assumes the position of FIG. 4. Locking portion 3S has-been moved from raised portion 34, allowing raised portion 34 to be biased away from plunger rod 20 by spring 25. Since the pressure of locking lever 30 is now released fromcam member 24, cam member 24 is freely rotatable on pivot portion 22.

In order to lock the cam member 24, actuating bar 14 is moved to the position shown in FIG. 3 by depression of pushbutton 10. In this position, the locking portion 38 constrains the raised portion 34 of the lever 30, moving the raised portion toward plunger rod 20 causing the lever to flex at its fixed end providing a lever effect, a

substantial clamping force on cam member 24. In this way the cam member can be ylocked easily by depression of the pushbutton 10. The action of T lug 18 butting against the end ,of guide slot 19 governs the extent of the relative movement of actuating bar 14 to plunger rod 20.

Returning toFlG. 2, itmay be seen that when push-l button 1t! is depressed suliiciently to cause locking of cam member 24, the cam member is also positioned at the same angle as parallel bar members 52. Thus, when bias spring 58 returns the pushbutton tothe normal position, that is with butt portion 60 of fplunger rod 20 butted against chassis 42, slug 44 may be returned to the preset position merely by depressing pushbutton 10 andhence the entire assembly against spring 58' causing cam member 24 to bring parallel bars 52 into alignmentwith the surface thereof.

Link section 56 Since there are relativelyfew parts, and no rivets in the:`

device, its assembly is simple'.` Cam member 24 andl leaf spring 25 are placed on plunger rodv 20 in proper position, the cam member fitting on pivot portion 22, and the spring held by tab 29 and pin 27. Locking key 32 of resilient locking leverl 38 is then inserted into locking key slot 2S of flange portion 26 'on plunger rod 28,' locking lever 30 beingY disposed along the length of `plunger rod 26. Lever 3) thereby holds cam member 24 and leaf spring 25 in their respective positions; T lug 18 is then inserted -in guide slot 1dV of slidable actuating bar 14; Plunger rod 20 -and locking lever 30 are pressed together against the bias of spring 25 and pivoted intohook shaped locking portion 38 through the opening therein. Actuating bar 14 is then moved to bring locking portion 38 into engagement with raised portion 34 of lever 38, locking cam member` 24 in position. The assembly is now completeV and ready for insertion into the radio receiver.

FIGS. 7y and 8 depict a second embodiment of the invention. Guide slot 16 in actuating bar 14 has a widened portion 16a` at one end thereof;` The provision of widened portion 16ak in slot 16 permits entryof T lug 18 into slot 16 without the necessityof turning plunger rod 2t) at approximately right angles to actuating bar 14, T lug 1S after assembly, is prevented from traveling far enough to align itself with widened portion 16a `by means of stop lug 70 on locking lever-305 When the device is unlocked, stop lug 70 willengage locking portion38 to limit movement of plunger rod 20. This eliminates the possibility of T lug 18 slipping out` of slot 16 through widened portion 16a dueto vibration of the device. If removal does become necessary afterv the device has been assembled, raised portion 34 need only be pressed toward plungenrod 20 allowing stop lug 70 to slip under locking portion 3S.

FIGS. 9, 10 and 11 show a thirdembodiment of the invention. The slot 16 in actuating bar 14 of the previous two embodiments has been eliminated in actuating bar 75. Instead of a T -lug 18, as in the prior embodiments, plunger rod '77 is providediwithanv L portion 80 at one end thereof. An opening 32 is provided; in LV portion 80 lto permit passage therethrough .of actuating bar 75. Thus, in this embodiment, actuating bar slides freely in. opening -82 necessitating the provision of limitations .'onthe linear movement of `actu-ating -bar 75 in orderto properly position locking portion 38 in locked and unlocked positions. To accomplish this, plunger rod 77 is provided with a punched out stop portion 96 thereon, which engagesv `a flanged portion 91dofV actuating bar 75 when :the device is in vlocked position. Linear movement of actuating bar 75 in unlocked position is limited by shoulders S4, 86, provided on the sides of actuating bar 75, which engages L portion 30 of plunger rod 77. This is depicted in the dotted position of FIG. l0.

Assembly of this embodiment is accomplished after placement of cam member 24, spring 25,.andV lever 30 as are the prior embodiments, merely by inserting the end of actuating bar 75 in opening 82wand .Y continuing to push therein until flanged portion 91 slips behind Ystop portion 90.

The invention provides, therefore, a locking mechanism for locking a cam member 'on a pushbutton plunger rod Vin a desired angular position, which locking mechanism contains few component parts and is-therefore relatively simple and inexpensive to manufacture. Furthermore, the need for rivets is dispensed. with, allowing rapid assembly without tools' and lending itself to automation.

I claim:

1. A pushbutton slide mechanism for use in presentable pushbutton tuners including in` combination, a pushbutton operated slidable .actuating lbar having a guideslot therein, a plunger rod having an opening therein andtfurther having a T lug thereon slidable in said guide slot and removable therefrom, said plunger: rod further having a projectionpivot post `having a free end, a cam member disposed againstsaid plunger rod and having an opening therein removably mating-with said pivot post,

a resilient elongated locking lever having an end removably mating with said opening in said plunger rod and being adapted to hold said cam member against said plunger rod, said actuating bar having -a locking portion adapted to move said lever with respect to said plunger rod upon movement of said actuating bar relative to said plunger rod to cause said locking lever to exert a clamping-force on said cam member 4and hold said cam member in xed position with respect to said plunger rod, said locking portion being generally hooked shaped to permit placement of said plunger rod and said lever therein through the opening side thereof, and spring means positioned between said plunger rod and said locking lever to bias said plunger rod against said actuating bar and said locking lever against said locking portion.

2. A rivetless pushbutton slide mechanism for use in presentable pushbutton tuners for radio receivers, said slide mechanism including in combination, a pushbutton operated slidable actuating bar having a guide slot therein, a plunger rod having a T lug thereon slidable in said guide slot and removable therefrom, said plunger rod further having a locating slot and a projecting pivot post having a free end, a cam member disposed against said plunger rod and having an opening therein removably mating with said pivot post and adapted for positioning a tuning apparatus, a locking lever one end of which has a raised portion, means on said plunger rod engaging the other end of said locking lever and releasably holding the same for pivotal movement with respect to said plunger rod, said locking lever being adapted to hold said cam member against said plunger rod and further adapted when said raised portion is positioned relatively close to said plunger rod to lock said cam member against rotation by applying pressure thereon, said actuating bar having a hook shaped integral locking portion shaped to permit placement of said plunger rod and said locking lever therein through the open side thereof, an extruded locating projection on said locking lever, a leaf spring having a locating opening and a locating tab portion, said spring being positioned between said plunger rod and said locking lever rand positioned by engagement between said locating projection and said locating opening, and by engagement between said locating tab portion and said locating slot in said plunger rod, said spring serving to bias said plunger rod against said actuating bar and to bias said locking lever against said locking portion, whereby movement of said slidable actuating bar such that said locking portion thereof engages said raised portion of said lever causes movement of said lever into engagernent with said cam member to lock the same against rotation.

3. A preset-table pushbutton slide mechanism including in combination, a slidable actuating bar and a plunger rod having mutually engageable means removably holding said actuating bar and said plunger rod in slidable relationship, said mutually engageable means being disengageable when said plunger rod is pivotal with respect to said actuating bar, said plunger rod further having an opening therein and further having 'a pivot post projecting therefrom with a free end, a cam member disposed against said plunger rod and having an opening therein removably receiving said pivot post, an elongated locking lever having an end removably held in said opening in said plunger rod and being adapted to hold said cam member against said plunger rod, said actuating bar having an integral hook shaped locking portion adapted to move said lever with respect vto said plunger rod upon movement of said actuating bar relative to said plunger rod to cause said locking lever to exert frictional force on said cam member and hold said cam member in fixed position with respect to said plunger rod, said hook shaped locking portion having an open side to receive said plunger rod and said lever therethrough when said plunger rod and said locking lever are pivoted with respect to said actuating bar to facilitate assembly and disassembly.

4. A presettable pushbutton slide mechanism including in combination, a slidable actuating bar and a plunger rod having mutually engageable means removably holding said actuating bar and said plunger rod in slidable relationship, said mutually engageable means being disengageable when said plunger rod is pivoted with respect to said actuating bar, said plunger rod further having an outwardly projecting portion having a slot therein, a pivot post with a free end projecting from said plunger rod, a cam member disposed against said plunger rod and having an opening therein removably receiving said pivot post, an elongated locking lever having a notched end removably captured in said slot in said outwardly extending portion of said plunger rod and being adapted to hold said cam member against said plunger rod, said actuating bar having an integral hook shaped locking portion adapted to move said lever toward said plunger rod upon movement of said actuating bar relative to said plunger rod to cause said locking lever to exert frictional force on said cam member `to hold said cam member in iixed position with respect to said plunger rod, resilient means biasing said locking lever against said locking portion, said hook shaped locking portion having an open side permitting movement of said plunger rod .and said locking lever therethrough as said plunger rod is pivoted with respect to said actuating bar, whereby said slide mechanism may be assembled and disassembled respectively by pivoting said plunger rod and said locking lever into and out of said locking portion.

References Cited by the Examiner UNITED STATES PATENTS 2,266,711 12/41 Crosby et al. 74-1033 2,301,090 11/42 Teaf 74-10.33 2,489,544 11/49 Schwarz et al. 74-10.33 2,659,236 11/53 Allen 74-10.33 2,793,531 5/57 Thompson 74-1033 2,800,027 7/57 Schwarz 74-10.33 2,930,241 3/60 Roback 74-1033 3,086,401 4/63 Horton 74-1033 FOREIGN PATENTS 742,939 1/56 Great Britain.

BROUGHTON G. DURHAM, Primary Exunftz'ner.I 

1. A PUSHBUTTON SLIDE MECHANISM FOR USE IN PRESENTABLE PUSHBOTTON TURNERS INCLUDING IN COMBINATION, A PUSHBUTTON OPERATED SLIDABLE ACTUATING BAR HAVING GUIDE SLOT THEREIN, A PLUNGER ROD HAVING AN OPENING THEREIN AND FURTHER HAVING A T LUG THEREON SLIDABLE IN SAID GUIDE SLOT AND REMOVABLE THEREFROM, SAID PLUNGER ROD FURTHER HAVING A PROJECTION PIVOT POST HAVING A FREE END, A CAM MEMBER DISPOSED AGAINST SAID PLUNGER ROD AND HAVING AN OPENING THEREIN REMOVABLY MATING WITH SAID PIVOT POST, A RESILIENT ELONGATED LOCKING LEVER HAVING AN END REMOVABLY MATING WITH SAID OPENING IN SAID PLUNGER ROD AND BEING ADAPTED TO HOLD SAID CAM MEMBER AGAINST SAID PLUNGER ROD, SAID ACTUATING BAR HAVING A LOCKING PORTION ADAPTED TO MOVE SAID LEVER WITH RESPECT TO SAID PLUNGER ROD UPON MOVEMENT OF SAID ACTUATING BAR RELATIVE TO SAID PLUNGER ROD TO CAUSE SAID LOCKING LEVER TO EXERT A CLAMPING FORCE ON SAID CAM MEMBER AND HOLD SAID CAM MEMBER IN FIXED POSITION WITH RESPECT TO SAID PLUNGER ROD, SAID LOCKING PORTION BEING GENERALLY HOOKED SHAPED TO PERMIT PLACEMENT OF SAID PLUNGER ROD AND SAID LEVER THEREIN THROUGH THE OPENING SIDE THEREOF, AND SPRING MEANS POSITIONED BETWEEN SAID PLUNGER ROD AND SAID LOCKING LEVER TO BIAS SAID PLUNGER ROD AGAINST SAID ACTUATING BAR AND SAID LOCKING LEVER AGAINST SAID LOCKING PORTION. 